Electric relay.



"damn? PATENTED MAR. 10, 1908.

B- WESTON. ELECTRIC RELAY.

APPLICATION FILED mm: 21 1904 2 SHEETS-SHEET 1.

PATENTED MAR. 10, 1908;

E. WESTON.

ELECTRIC RELAY.

urmcuxou rILnn JUNE 21. 1904.

2 SHEETS-SHEET 2.

EDWARD WESTON, OF NEWARK, NEW JERSEY.

' ELECTRIC RELAY.

Specification 01 Letters Patent.

Patented March 10, 1908,

Application filed June 21, 1904. Serial No. 213,500.

To all whom it may concern:

Be it known that I, EDWARD WESTON, a subject of the King of Great Britain, residing at Newark, county of Essex, and State of New Jersey, have made a new and useful Invention in Electric Relays, of which the following is a specification.

My invention is directed particularly to improvements in that type of electric relays in which the movable contacts carried by the.

relay armature lever close local circuits on stationary front and back contact stops, said armature lever being controlled by electromagnetic coils located on opposite sides thereof, such instruments being known in the art as double contact relays, and it has for its objects :First, to maintain the armature le ver in a position substantially equidistant between the two poles of the two independent controlling or operating relay electromagnets located on opposite sides of said. lever.- Second, to make the apparatus simple and; positive in its adjustments and in such manner that the stationary contacts cannot be-thrown out of relation with the adjustable contacts which close the circuits on either side of the armature lever dependent upon which magnet is excited by the operating current.

My improved relay is designed to be used in such manner as to operate without there being the slightest danger of any false backcontact when the armature lever is released from either of the operating or controlling magnets; that is to say in such manner as to revent the possibility of the armature lever alling back sufficiently beyond its normal position of rest to make a false contact by its swing on either one side or the other.

M novel relay has an especial utility also in i the act that it is designed to operate with the slightest possible force and in such manner as to close the circuit on either one or the other of the adjustable contact screws and avoid any false contact. The normal position of the armature lever of this instrument is practically equidistant from the opposite contacts and, consequently, from the poles of the opposing magnets, so that it can be moved from this position quickly and by the least possible application of force applied on either side of its path of motion.

Relays ofthis type as heretofore devised have usually been provided with retractile springs located on opposite sides of the armature lcvcr and with means for independently adjusting said springs. I haveascertained that with relays of this nature the best results cannot always be obtained. for the following reasons; first, because it is not always possible to construct two retractile.

springs of exactly the same tensile strength.

and dimension; second, it is not always possible to provide and apply adjusting means. which shall so e ually centra 'ze the armar. ture lever as to o tain like resultsat the op: posite contacts when the same is vibrated back and forth.

For a full and clear understanding of the invention such as will enable others skillediin the art to construct and use the same, refere ence is had to the accompanying drawings, in which,

Figure 1 illustrates a plan view of arelay. constructed in accordance with my im rovement, and Fig. 2 is a side elevationa View. thereof as seen looking thereat from the bottom toward the top of the drawings. 3. is a transverse sectional view taken through Fig. 2 at substantially the center of them.- strument and as seen looking thereat from left to right, Fig. 4 being a similar sectional view showing a. spiral retractilespring and rigid support in place of the flat t pe ofspring and yielding support illustrate in the other figures of the drawings.

R eferring to the drawings in detail, 1 represents the base of the instrument. preferably. of insulating material, and 2, 2, the relay. electromagnets of usual type secured directly. thereto by angle irons 3, 3, and screws.

4, 4, 4, represent the binding postswhich are connected to the coils of the magnets and designed to be connected in a main line circuit in the usual Way.

5, 5, represent two of the bindingposts for the local circuits secured directly to a cond ucting cross-bar 8 resting upon a bar of insulating material 7 which in turn is secureddirectly to the base of the instrument by standards 6, 6.

9, 9 are the adjustable contact points forthe relay secured in lateral integral extensions of the cross-bar 8 (see Fig. 1).

10 is the armature lever pivotally support-- ed upon trunnions in the usual manner be.- tween the poles of the electromagnets 2, 2,

and provided at its upper end with a con-- ducting bar 11, to which the movable contacts are directly secured, 12 being, as shown in Figs. 1, 2 and 3, a thin flat spring of the; desired elasticity and provided at its upper I end with means in the nature of screwthreaded partsa nut 17 and a set-screw 18for adjustably securing it to a yielding comlucting arm 15 suppmtted in turn by a conducting standard 14 secured directly to the insulatingbase 1 (see Fig. 3).

13 is the third or additional local binding post, the circuit relations being of the ordinary nature whereby two local sounders or translating devices may be operated from a single battery, as will be readily understood by those skilled in the art. By thus pivotally supporting the armature lever 10 at its lower end and securing the free or independent end thereof by a yielding spring 12 adjustably secured as described to a yielding arm 15, I am enabled to effect the adjustment of the vibratory contacts carried by the armature lever with relation to the adjust able stationary contacts 9, 9, with the greatest degree of nicety and be assured of having the same effect in the local circuits when the same are closed on opposite sides by the vibrating action of the armature lever.

In Fig. 4 I have illustrated a spiral retraetile spring adjustably secured at its up per end to a rigid arm 15 and having its axis coated in alinement with the pivot supports and so arranged as above described that when the adjustment is perfectly effected the poles of the magnets 2, 2, located on opposite sides of the armature will produce the same effect as is produced by the modified arrangement shownin Fig. 3 and give equally good results.

I/Vith a relay as thus constructed the armature is kept in a position substantially equidistant between the poles of the two independently operating electromagnets 2, 2, located upon the opposite sides thereof, and is of the'simplest and most positive nature in its adjustment and operation, the arrangement being such that the armature contacts cannot be thrown out of relation to the adjustable stop contacts which close the circuit on either one side or the other, according to which magnet is energized. This type of relay has an especial utility in systems of electrlcal energy where it is desired to utilize a local current on either side of the system, and to effect this result positively and without the slightest danger of there being a false back contact when the armature is released; that is to say, in such manner as to prevent any possibility of the armature flying back so far beyond its normal position of rest that it will make a false contact by reason of its inertia or over-throw. The armature of such an instrument is also adapted to move with the slightest possible electrical energy and is of the most delicate nature, its normal position being absolutely equidistant from the opposite front and back contacts and, con sequently, from the opposite or opposing poles of the magnets it can be moved quickly 1 is broadly new with me to so devise a double contact relay that the retraetile effect will be alike or substantially alike for the double vibrations of the armature lever, and my claims are designed to be of the most generic scope in this respect. Nor do I limit my invention to any specific use, as it may be utilized anywhere in the art where a double contact relay is required, there being many such uses as is obvious to those skilled in the art.

The principal use to which I propose to apply this instrument is that of starting, stopping, or reversing the direction of motion of an electric motor employed to drive a recording instrument either for electrical or other purposes, this form of relay making it impossible that a motor so controlled shall make any false registration upon the record sheet by reason of false back-contacts.

The preferred form of my invention is illustrated in Figs. 2 and 3 of the drawin s.

Having thus described my invention w at I claim and desire to secure by Letters Patent of the United States is- 1. A relay provided with a pair of electromagnets; an armature lever pivotally supported at one end between the poles of said magnets; a retractile spring secured to the free end'of said lever and to a stationary support located in alinement with the axis thereof; in combination with movable and stationary contacts located intermediate the pivoted end of the armature lever and the stationary support for the retraetile means, said retraetile means being provided with adjusting means for placing it under tension, the arrangement being such that normally the armature lever and its retraetile means are located in the same plane and the stationary contacts at equal distances on opposite sides from the movable contacts, substantially as described.

2. A relay provided with a pair of electromagnets and an armature lever pivotally supported at one 'end between the poles thereof; a pair of stationary contacts located on opposite sides of the armature lever and intermediate the ends thereof, said contacts being electrically connected to and supported by a conducting bar secured to the'base 0f the instrument by standards located on opposite sides of the electromagnets in combination with yielding retraetile means secured to the free end of the armature lever and to a standard supported also by the base;

together with movable contacts carried by the armature lever, the lever, the retraetile means and the supporting end of the standard being normally in alinement and the 5 arrangement such that the forces opposing the action of the magnets is always equal, substantially as described. 

